U.S. Pat. No. 6,390,520, assigned to Hanchett Entry Systems, Inc., describes a surface-mounted electric door strike which provides the capability of releasing a door latch of the type normally used by a rim panic exit device. The name for this particular lock set is derived from the fact that it is mounted on an exit door, has a latch that engages with the rim portion of the door jamb and is used for egress especially in panic situations. The above-mentioned patent uses transmission and release levers mounted to the housing to accomplish release or locking of the keeper or keepers.
In addition, this patent incorporates fail safe and fail secure modes of operation, the switching between which is accomplished by resetting the starting position for the release lever and repositioning the actuating coil thus giving a three state; locked, unlocked, and locked capability.
The device set forth herein provides a simplified method of controlling the locked, or unlocked state of the keepers while maintaining the capability of providing fail safe or fail secure operation.